Island



(No Model.)

J. MUIR. EXPANSION PULLEY.

Patent edApr. 14, 1896.

AN DREW EERAHAM. PHOTOMTHQWASMI Newman.

- To all whom it may concern:

Be it known that 1, JAMES MUIR, a subject UNITED I STATES PATENT OFFICE.

JAMES MUIR, OF PROVIDENCE, RHODE ISLAND.

EXPANSION-=PULLEY.

SPECIFICATION forming part of Letters Patent No. 558,196, dated April14, 1896. Application filed November 22, 1895. Serial No. 569,784. (NomodeLl of the Queen of. Great Britain, residing at Providence, in thecounty of Providence and State of Rhode Island, have invented certainnew and useful Improvements in Expansion- Pulleys; and I do herebydeclare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and usethe same, reference being had to theaccompanying drawings, and to letters of reference marked thereon, whichform a part of this specification.

My invention relates to the class of pulleys in which the rim portionsconsist of a series of radially-movable sectors; and it consists in thearticle of manufacture hereinafter described, and set forth by theclaims.

The object I have in view is to produce a pulley of the class referredto capable of being easily and readily expanded or contracted while itis in motion and revolving in either direction. In certain kinds ofmachinery or machinesas, for example, such as are usually employed inpaper making and calendering-it frequently becomes necessary to changetheir speed of rotation during the production of the goods undermanufacture, and in order to effect such change in speed the machine mayhave to be stopped, so that the attendant can make the necessaryadjustment of the driving mechanism with safety. Obviously such stoppingand starting of the machinery involves the loss of time and product, thelatter being more or lessinjuriously affected thereby.

By means of my improved pulley the speed of the machine driven by it maybe changed so as to run above or below the normal speed, as desired, andwithout first stopping it or even reducing its speed to effect suchchange.

In the accompanying sheet of drawings, Figure 1 is a front or end viewof my improved expanding pulley, the segments or rim-sections contractedto the minimum diameter, portions of the front plates, &c., being brokenaway. Fig. 2 is a side view in partial section. Fig. 3 is a front viewsimilar to Fig. 1, but showing the pulley expanded; and Fig. 4c is anend view showing a modification of the gear-controlling device. I

In the drawings, A indicates my improved expanding pulley complete. Itis provided with a center or hub portion b, capable of being secured toa shaft 3. Said hub, as drawn, has a series of six spokes or integralarms I) radiating therefrom, in which are movably seated a correspondingseries of sector-arms a, these latter carrying at their outer ends theseveral rim-sectors a. The sector-arms or spokes are hollow and areprovided centrally at their lower ends with nuts 0?. latter are radiallyarranged, each having fitted thereto'a screw-threaded spindle e. Thespindles are non-movable endwise and are mounted in bearings formed insaid hub member I), and are maintained in place by means of a removablecap-ring on. (See Fig. 2.) In order to keep the arms a and said cap-ringin position laterally or longitudinally of the shaft, as well as toprotect said members, I provide a fiat spider-shaped cap-plate t, thewhole being secured together by bolts n.

The inner or lower ends of the spindles e have secured thereto smallbevel-gears f, one gear to each spindle. Intergearing therewith at therear side of the pulley is a central gear 0, the same having anelongated hub 0, extending toward the front of the pulley and mounted toturn loosely on the extension b of said hub b. A gear h, similar to gear0, intergears with the front side of the several gears f. Said gear hisoppositely-arranged with respect to gear 0, and is mounted to turnloosely on the hub c of the latter. The gear 77. is provided with anenlarged round wheel-rim it, through which the gear maybe rotated.

To the front end of the gear-hub c is se- These.

cured an operating-wheel 0 also provided a with a rim portion,substantially as just stated with respect to gear h. The hub of wheel 0serves to hold the gear h in position laterally. Thus it will be seenthat by turning the wheel 0 in either direction a corresponding movementwill be imparted to the gear 0. The gear h may be rotated in like mannerby turning the wheel h.

Assuming now the several parts to be arranged substantially asrepresented in Figs. 1 and 2, the pulley being stationary, and that thespindles e are provided, say, with right hand screw-threads, it will beapparent that upon turning the wheel 0 to the right, or in the directionthe hands of a watch travel, the gears c and fwill cause the spindles torevolve simultaneously toward the left, thereby forcing the severalrim-sectors outwardly and expanding the pulley. A reversal of theoperation contracts the pulley.

By means of the wheel-rim h the front central gear h, &c., are employedfor expanding and contracting the pulley-rim. In this case, however, themovement of the gear h is reversed with respect to the gear cthat is tosay, turning the wheel-rim h to the left operates to expand the pulleyand turning it to the right contracts it.

The principal advantage or utility of my invention resides in the factthat the pulley may be both expanded and contracted while it isrevolving in either direction and at any rate of speed. Moreover, thetwo gears c h and the corresponding wheel-rims c h act as a positivecheck each upon the other automatically to hold the revolving pulleyrimin a locked position after adjustment.

In effecting the adjustment of the revolving pulley A it is simplynecessary to hold one of the hand-wheels or rims stationary, or toretard its movement until the desired adjustment is accomplishedthat is,suppose the pulley is to be expanded, and assuming it to be revolving inthe arrow direction. shown in Fig. 1, the operator simply holds thewheel-rim 0 thereby causing the spindles to revolve axially, and thusforce the rim sectors outwardly to the desired extent. While this istaking place the other wheel-rim and gear h will thereby be accelerated,or, in other words, the speed of the revolving gear It will for the timebeing exceed the speed of the pulley. The pulley is contracted byholding the wheel-rim 7t, whereby the gearing, &c., causes the spindlese to revolve axially in a reverse direction, the rotation of thewheel-rim c and its gear being accelerated in turn. In case the pulleyis driven in a reverse direction to that indicated by said arrow in Fig.1, then in that event the pulley is expanded by holding the wheel-rim hand is contracted by holding the rim 0 In lieu of holding the wheel-rimsand thereby the gears c h by hand, they maybe effectually held orchecked, while the pulley is revolving very rapidly, through the mediumof straps or brakes capable of being brought into frictional engagementwith them, substantially as represented in reduced scale in Fig. 4,wherein the said gears are provided with small pulley-like hubs. A pairof suitably constructed and mounted brake-levers'v oare alsorepresented, the same being so arranged with respect to said hubs thatthey may be readily swung into and out of frictional contact with thehubs, as desired. It is obvious, too, that brake-levers may be employedto frictionally engage the surface of the said wheel-rin1s c h withoutdeparting from the spirit of the invention.

From the foregoing description it will be evident that by means of myimprovement expanding pulleys may be easily and quickly adjusted whilethey are revolving at any speed and in either direction, the device alsoforming an automatic locking arrangement for maintaining the rim-sectorsin position when adjusted.

Vhile I do not claim, broadly, as my invention an expanding pulleycapable of being expanded and contracted while it is in motion,

WVhat I do claim is 1. In an expanding pulley, the combination of acentral hub portion adapted to be socured to a driving-shaft said hubhaving a series of radial spokes, rim-sectors provided with arms movablymounted in said spokes each having a nut or female screw, a revolublescrew mounted in each of said hub-spokes coacting with said nuts,bevel-gears secured to the inner ends of said screws, a loosely-'mounted central gear intergearing with all of said bevel-gears capableof being revolved in either direction, and a central gear oppositelyfacing the first-named central gear also intergearing with all thebevel-gears and capable of being revolved in either direction at will,substantially as hereinbefore described.

2. In an expanding pulley, the combination with the central or drivingmember, a series of radiallymovable rim sector members mounted thereon,a series of coacting screws and nuts arranged in said driving and sectormembers and gears, as f, secured to theinner or lower ends of saidscrews, of a pair of oppositely facing loosely turning central gears, asc, h, in continuous engagement with the adjacent sides of said gears f,and a pair of operating wheels or members secured to said central gears,said operating-wheels being arranged at one side of the pulley andcapable of being rotated simultaneously in opposite directions,substantially as set forth.

In testimonywhereof I have affixed my signature in presence of twowitnesses.

J AMES MUIR.

Witnesses:

GEo. II. REMINGTON, REMINGTON SHERMAN.

IIO

